<h1>Unsubscribing to an Observable</h1>
<div class="div-container">
    <div class="sub-container">
        <h2>Subscriber 1</h2>
        <hr />
        <div class="data-list" *ngFor="let x of [10, 20, 30, 40]">
            {{ x }}
        </div>
        <button>Subscribe</button>
        <button>Unsubscribe</button>
    </div>
</div>


